fs/partitions/check.c

   1 /*
   2  *  fs/partitions/check.c
   3  *
   4  *  Code extracted from drivers/block/genhd.c
   5  *  Copyright (C) 1991-1998  Linus Torvalds
   6  *  Re-organised Feb 1998 Russell King
   7  *
   8  *  We now have independent partition support from the
   9  *  block drivers, which allows all the partition code to
  10  *  be grouped in one location, and it to be mostly self
  11  *  contained.
  12  *
  13  *  Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/fs.h>
  19 #include <linux/kmod.h>
  20 #include <linux/ctype.h>
  21 #include <linux/devfs_fs_kernel.h>
  22
  23 #include "check.h"
  24 #include "devfs.h"
  25
  26 #include "acorn.h"
  27 #include "amiga.h"
  28 #include "atari.h"
  29 #include "ldm.h"
  30 #include "mac.h"
  31 #include "msdos.h"
  32 #include "osf.h"
  33 #include "sgi.h"
  34 #include "sun.h"
  35 #include "ibm.h"
  36 #include "ultrix.h"
  37 #include "efi.h"
  38
  39 #ifdef CONFIG_BLK_DEV_MD
  40 extern void md_autodetect_dev(dev_t dev);
  41 #endif
  42
  43 int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
  44
  45 static int (*check_part[])(struct parsed_partitions *, struct block_device *) = {
  46         /*
  47          * Probe partition formats with tables at disk address 0
  48          * that also have an ADFS boot block at 0xdc0.
  49          */
  50 #ifdef CONFIG_ACORN_PARTITION_ICS
  51         adfspart_check_ICS,
  52 #endif
  53 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
  54         adfspart_check_POWERTEC,
  55 #endif
  56 #ifdef CONFIG_ACORN_PARTITION_EESOX
  57         adfspart_check_EESOX,
  58 #endif
  59
  60         /*
  61          * Now move on to formats that only have partition info at
  62          * disk address 0xdc0.  Since these may also have stale
  63          * PC/BIOS partition tables, they need to come before
  64          * the msdos entry.
  65          */
  66 #ifdef CONFIG_ACORN_PARTITION_CUMANA
  67         adfspart_check_CUMANA,
  68 #endif
  69 #ifdef CONFIG_ACORN_PARTITION_ADFS
  70         adfspart_check_ADFS,
  71 #endif
  72
  73 #ifdef CONFIG_EFI_PARTITION
  74         efi_partition,          /* this must come before msdos */
  75 #endif
  76 #ifdef CONFIG_SGI_PARTITION
  77         sgi_partition,
  78 #endif
  79 #ifdef CONFIG_LDM_PARTITION
  80         ldm_partition,          /* this must come before msdos */
  81 #endif
  82 #ifdef CONFIG_MSDOS_PARTITION
  83         msdos_partition,
  84 #endif
  85 #ifdef CONFIG_OSF_PARTITION
  86         osf_partition,
  87 #endif
  88 #ifdef CONFIG_SUN_PARTITION
  89         sun_partition,
  90 #endif
  91 #ifdef CONFIG_AMIGA_PARTITION
  92         amiga_partition,
  93 #endif
  94 #ifdef CONFIG_ATARI_PARTITION
  95         atari_partition,
  96 #endif
  97 #ifdef CONFIG_MAC_PARTITION
  98         mac_partition,
  99 #endif
 100 #ifdef CONFIG_ULTRIX_PARTITION
 101         ultrix_partition,
 102 #endif
 103 #ifdef CONFIG_IBM_PARTITION
 104         ibm_partition,
 105 #endif
 106         NULL
 107 };
 108
 109 /*
 110  * disk_name() is used by partition check code and the genhd driver.
 111  * It formats the devicename of the indicated disk into
 112  * the supplied buffer (of size at least 32), and returns
 113  * a pointer to that same buffer (for convenience).
 114  */
 115
 116 char *disk_name(struct gendisk *hd, int part, char *buf)
 117 {
 118         if (!part)
 119                 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
 120         else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
 121                 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
 122         else
 123                 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, part);
 124
 125         return buf;
 126 }
 127
 128 const char *bdevname(struct block_device *bdev, char *buf)
 129 {
 130         int part = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor;
 131         return disk_name(bdev->bd_disk, part, buf);
 132 }
 133
 134 EXPORT_SYMBOL(bdevname);
 135
 136 /*
 137  * There's very little reason to use this, you should really
 138  * have a struct block_device just about everywhere and use
 139  * bdevname() instead.
 140  */
 141 const char *__bdevname(dev_t dev, char *buffer)
 142 {
 143         scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
 144                                 MAJOR(dev), MINOR(dev));
 145         return buffer;
 146 }
 147
 148 EXPORT_SYMBOL(__bdevname);
 149
 150 static struct parsed_partitions *
 151 check_partition(struct gendisk *hd, struct block_device *bdev)
 152 {
 153         struct parsed_partitions *state;
 154         int i, res;
 155
 156         state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
 157         if (!state)
 158                 return NULL;
 159
 160 #ifdef CONFIG_DEVFS_FS
 161         if (hd->devfs_name[0] != '\0') {
 162                 printk(KERN_INFO " /dev/%s:", hd->devfs_name);
 163                 sprintf(state->name, "p");
 164         }
 165 #endif
 166         else {
 167                 disk_name(hd, 0, state->name);
 168                 printk(KERN_INFO " %s:", state->name);
 169                 if (isdigit(state->name[strlen(state->name)-1]))
 170                         sprintf(state->name, "p");
 171         }
 172         state->limit = hd->minors;
 173         i = res = 0;
 174         while (!res && check_part[i]) {
 175                 memset(&state->parts, 0, sizeof(state->parts));
 176                 res = check_part[i++](state, bdev);
 177         }
 178         if (res > 0)
 179                 return state;
 180         if (!res)
 181                 printk(" unknown partition table\n");
 182         else if (warn_no_part)
 183                 printk(" unable to read partition table\n");
 184         kfree(state);
 185         return NULL;
 186 }
 187
 188 /*
 189  * sysfs bindings for partitions
 190  */
 191
 192 struct part_attribute {
 193         struct attribute attr;
 194         ssize_t (*show)(struct hd_struct *,char *);
 195 };
 196
 197 static ssize_t
 198 part_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
 199 {
 200         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 201         struct part_attribute * part_attr = container_of(attr,struct part_attribute,attr);
 202         ssize_t ret = 0;
 203         if (part_attr->show)
 204                 ret = part_attr->show(p,page);
 205         return ret;
 206 }
 207
 208 static struct sysfs_ops part_sysfs_ops = {
 209         .show   =       part_attr_show,
 210 };
 211
 212 static ssize_t part_dev_read(struct hd_struct * p, char *page)
 213 {
 214         struct gendisk *disk = container_of(p->kobj.parent,struct gendisk,kobj);
 215         dev_t dev = MKDEV(disk->major, disk->first_minor + p->partno);
 216         return print_dev_t(page, dev);
 217 }
 218 static ssize_t part_start_read(struct hd_struct * p, char *page)
 219 {
 220         return sprintf(page, "%llu\n",(unsigned long long)p->start_sect);
 221 }
 222 static ssize_t part_size_read(struct hd_struct * p, char *page)
 223 {
 224         return sprintf(page, "%llu\n",(unsigned long long)p->nr_sects);
 225 }
 226 static ssize_t part_stat_read(struct hd_struct * p, char *page)
 227 {
 228         return sprintf(page, "%8u %8llu %8u %8llu\n",
 229                        p->reads, (unsigned long long)p->read_sectors,
 230                        p->writes, (unsigned long long)p->write_sectors);
 231 }
 232 static struct part_attribute part_attr_dev = {
 233         .attr = {.name = "dev", .mode = S_IRUGO },
 234         .show   = part_dev_read
 235 };
 236 static struct part_attribute part_attr_start = {
 237         .attr = {.name = "start", .mode = S_IRUGO },
 238         .show   = part_start_read
 239 };
 240 static struct part_attribute part_attr_size = {
 241         .attr = {.name = "size", .mode = S_IRUGO },
 242         .show   = part_size_read
 243 };
 244 static struct part_attribute part_attr_stat = {
 245         .attr = {.name = "stat", .mode = S_IRUGO },
 246         .show   = part_stat_read
 247 };
 248
 249 static struct attribute * default_attrs[] = {
 250         &part_attr_dev.attr,
 251         &part_attr_start.attr,
 252         &part_attr_size.attr,
 253         &part_attr_stat.attr,
 254         NULL,
 255 };
 256
 257 extern struct subsystem block_subsys;
 258
 259 static void part_release(struct kobject *kobj)
 260 {
 261         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 262         kfree(p);
 263 }
 264
 265 struct kobj_type ktype_part = {
 266         .release        = part_release,
 267         .default_attrs  = default_attrs,
 268         .sysfs_ops      = &part_sysfs_ops,
 269 };
 270
 271 void delete_partition(struct gendisk *disk, int part)
 272 {
 273         struct hd_struct *p = disk->part[part-1];
 274         if (!p)
 275                 return;
 276         if (!p->nr_sects)
 277                 return;
 278         disk->part[part-1] = NULL;
 279         p->start_sect = 0;
 280         p->nr_sects = 0;
 281         p->reads = p->writes = p->read_sectors = p->write_sectors = 0;
 282         devfs_remove("%s/part%d", disk->devfs_name, part);
 283         kobject_unregister(&p->kobj);
 284 }
 285
 286 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len)
 287 {
 288         struct hd_struct *p;
 289
 290         p = kmalloc(sizeof(*p), GFP_KERNEL);
 291         if (!p)
 292                 return;
 293
 294         memset(p, 0, sizeof(*p));
 295         p->start_sect = start;
 296         p->nr_sects = len;
 297         p->partno = part;
 298
 299         devfs_mk_bdev(MKDEV(disk->major, disk->first_minor + part),
 300                         S_IFBLK|S_IRUSR|S_IWUSR,
 301                         "%s/part%d", disk->devfs_name, part);
 302
 303         if (isdigit(disk->kobj.name[strlen(disk->kobj.name)-1]))
 304                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%sp%d",disk->kobj.name,part);
 305         else
 306                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%s%d",disk->kobj.name,part);
 307         p->kobj.parent = &disk->kobj;
 308         p->kobj.ktype = &ktype_part;
 309         kobject_register(&p->kobj);
 310         disk->part[part-1] = p;
 311 }
 312
 313 static void disk_sysfs_symlinks(struct gendisk *disk)
 314 {
 315         struct device *target = get_device(disk->driverfs_dev);
 316         if (target) {
 317                 sysfs_create_link(&disk->kobj,&target->kobj,"device");
 318                 sysfs_create_link(&target->kobj,&disk->kobj,"block");
 319         }
 320 }
 321
 322 /* Not exported, helper to add_disk(). */
 323 void register_disk(struct gendisk *disk)
 324 {
 325         struct block_device *bdev;
 326         char *s;
 327         int err;
 328
 329         strlcpy(disk->kobj.name,disk->disk_name,KOBJ_NAME_LEN);
 330         /* ewww... some of these buggers have / in name... */
 331         s = strchr(disk->kobj.name, '/');
 332         if (s)
 333                 *s = '!';
 334         if ((err = kobject_add(&disk->kobj)))
 335                 return;
 336         disk_sysfs_symlinks(disk);
 337         kobject_hotplug(&disk->kobj, KOBJ_ADD);
 338
 339         /* No minors to use for partitions */
 340         if (disk->minors == 1) {
 341                 if (disk->devfs_name[0] != '\0')
 342                         devfs_add_disk(disk);
 343                 return;
 344         }
 345
 346         /* always add handle for the whole disk */
 347         devfs_add_partitioned(disk);
 348
 349         /* No such device (e.g., media were just removed) */
 350         if (!get_capacity(disk))
 351                 return;
 352
 353         bdev = bdget_disk(disk, 0);
 354         if (!bdev)
 355                 return;
 356
 357         bdev->bd_invalidated = 1;
 358         if (blkdev_get(bdev, FMODE_READ, 0) < 0)
 359                 return;
 360         blkdev_put(bdev);
 361 }
 362
 363 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 364 {
 365         struct parsed_partitions *state;
 366         int p, res;
 367
 368         if (bdev->bd_part_count)
 369                 return -EBUSY;
 370         res = invalidate_partition(disk, 0);
 371         if (res)
 372                 return res;
 373         bdev->bd_invalidated = 0;
 374         for (p = 1; p < disk->minors; p++)
 375                 delete_partition(disk, p);
 376         if (disk->fops->revalidate_disk)
 377                 disk->fops->revalidate_disk(disk);
 378         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 379                 return 0;
 380         for (p = 1; p < state->limit; p++) {
 381                 sector_t size = state->parts[p].size;
 382                 sector_t from = state->parts[p].from;
 383                 if (!size)
 384                         continue;
 385                 add_partition(disk, p, from, size);
 386 #ifdef CONFIG_BLK_DEV_MD
 387                 if (state->parts[p].flags)
 388                         md_autodetect_dev(bdev->bd_dev+p);
 389 #endif
 390         }
 391         kfree(state);
 392         return 0;
 393 }
 394
 395 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 396 {
 397         struct address_space *mapping = bdev->bd_inode->i_mapping;
 398         struct page *page;
 399
 400         page = read_cache_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 401                         (filler_t *)mapping->a_ops->readpage, NULL);
 402         if (!IS_ERR(page)) {
 403                 wait_on_page_locked(page);
 404                 if (!PageUptodate(page))
 405                         goto fail;
 406                 if (PageError(page))
 407                         goto fail;
 408                 p->v = page;
 409                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 410 fail:
 411                 page_cache_release(page);
 412         }
 413         p->v = NULL;
 414         return NULL;
 415 }
 416
 417 EXPORT_SYMBOL(read_dev_sector);
 418
 419 void del_gendisk(struct gendisk *disk)
 420 {
 421         int p;
 422
 423         /* invalidate stuff */
 424         for (p = disk->minors - 1; p > 0; p--) {
 425                 invalidate_partition(disk, p);
 426                 delete_partition(disk, p);
 427         }
 428         invalidate_partition(disk, 0);
 429         disk->capacity = 0;
 430         disk->flags &= ~GENHD_FL_UP;
 431         unlink_gendisk(disk);
 432         disk_stat_set_all(disk, 0);
 433         disk->stamp = disk->stamp_idle = 0;
 434
 435         devfs_remove_disk(disk);
 436
 437         if (disk->driverfs_dev) {
 438                 sysfs_remove_link(&disk->kobj, "device");
 439                 sysfs_remove_link(&disk->driverfs_dev->kobj, "block");
 440                 put_device(disk->driverfs_dev);
 441         }
 442         kobject_hotplug(&disk->kobj, KOBJ_REMOVE);
 443         kobject_del(&disk->kobj);
 444 }